1. Field of the Invention
The present invention relates to a printed circuit board (PCB) and, more particularly, to a PCB and a probe including the same for use in an ultrasound system that generates internal images of a patient body with ultrasound waves.
2. Description of the Related Art
Generally, an ultrasound system refers to a non-invasive apparatus that irradiates an ultrasound signal from a surface of a patient body towards a target internal organ beneath the body surface and obtains an image of a monolayer or blood flow in soft tissue from information in the reflected ultrasound signal (ultrasound echo-signal). The ultrasound system has been widely used for diagnosis of the heart, the abdomen, the urinary organs, and in obstetrics and gynecology due to various merits such as small size, low price, real-time image display, and high stability through elimination of any radiation exposure, as compared with other image diagnostic systems, such as X-ray diagnostic systems, computerized tomography scanners (CT scanners), magnetic resonance imagers (MRIs), nuclear medicine diagnostic apparatuses, and the like.
Particularly, the ultrasound system includes a probe which transmits an ultrasound signal to a patient body and receives the ultrasound echo-signal reflected therefrom to obtain the ultrasound image of the patient body.
The probe includes a transducer, a case with an open upper end, a cover coupled to the open upper end of the case to directly contact the body surface of the patient, and the like.
The transducer includes a piezoelectric layer in which a piezoelectric material converts electrical signals into sound signals or vice versa while vibrating, a coordination layer reducing a difference in sound impedance between the piezoelectric layer and a patient body to allow as much of the ultrasound waves generated from the piezoelectric layer to be transferred to the patient body as possible, a lens layer focusing the ultrasound waves, which travel in front of the piezoelectric layer, onto a predetermined point, and a backing layer blocking the ultrasound waves from traveling in a rearward direction of the piezoelectric layer to prevent image distortion.
The piezoelectric layer includes a piezoelectric device, and signal and ground electrodes provided to upper and lower ends of the piezoelectric device, respectively. Further, a PCB is bonded to the piezoelectric layer to be connected to the signal and ground electrodes in such a way that a bonding surface of the PCB is bonded to the ground electrode by an adhesive.
In such a probe, a bonding force between the piezoelectric device and the bonding surface of the PCB is low to cause unreliable bonding between the PCB and the piezoelectric layer, thereby deteriorating performance of the probe. Therefore, there is a need for an improved probe that overcomes such a problem.